1. Field of the Invention
The present invention relates to a fuel tank with a check valve attached to a fuel feed pipe fixed to a tank body.
2. Description of Related Art
Generally a check valve is provided in a fuel tank of an automobile to prevent liquid fuel and fuel vapor in the fuel tank from flowing in a reverse direction to be discharged to the atmosphere when filling the fuel tank. FIG. 21 is a partly sectioned, side view illustrating a conventional fuel tank 200 of an automobile that includes a fuel feed mechanism 210 attached to a side wall member 204 of a tank body 202 for feeding fuel into the tank body 202. The fuel feed mechanism 210 includes an inlet pipe 212 fixed to the side wall member 204, an inlet hose 214 connected to an opening of the inlet pipe 212, an inlet filler pipe 216 connected to an opening of the inlet hose 214, and a cap 218 attached to a fuel filler opening 216a of the inlet filler pipe 216. A canister (not shown) is further connected to the tank body 202 and receives the fuel vapor discharged from the tank body 202 when filling the tank.
A check valve 220, attached to an opening 212a of the inlet pipe 212, prevents liquid fuel and fuel vapor in the tank body 202 from flowing in a reverse direction to be discharged to the atmosphere when filling the tank body 202.
FIG. 22 is a perspective view illustrating the appearance of the check valve 220 that includes a support fitting 222 welded to an circumferential surface 212b of the inlet pipe 212, a valve member 226 rotatably attached to the support fitting 222 via a shaft element 224 for closing the opening 212a of the inlet pipe 212, and a coil spring 228 supported by the shaft element 224 for pressing the valve member 226 toward its normally closed position.
When a user removes the cap 218 and feeds a supply of fuel through the fuel filler opening 216a, the flow of fuel presses open the valve member 226 against the pressing force of the coil spring 228 and is fed into the tank body 202. The flow of fuel through the inlet pipe 212 strikes against the valve member 226 of the check valve 220 and falls down to be reserved in the tank body 202. When supplying the fuel into the fuel tank 200 is completed, the check valve 220 closes to prevent the liquid fuel and fuel vapor in the tank body 202 from flowing in a reverse direction and thereby discharging to the atmosphere.
When the temperature is relatively high wherein the saturated vapor pressure is increased, the tank body 202 of the fuel tank 200 fills with the fuel vapor. Accordingly, the supply of fuel into the tank body 202 forces the fuel vapor out of the tank body 202 and increases the volume of the fuel vapor flown into the canister.